It is well known that the ability of a person to speak is a basic need in society. One of the basic structures in the human body that allow for speech is the vocal folds (also known as “vocal cords”) located in the larynx and basically are twin infoldings of mucous membranes stretched horizontally across the larynx. Vocal folds, under normal circumstances, vibrate when a person attempts to speak, in a phenomenon known as phonation. The rhythmic opening and closing of the vocal folds provide a major component of human speech. Normally, the folds are pushed apart by subglottal pressure, with the inferior part of each fold leading the superior part. When one or both of the vocal folds fails to function correctly, a person may lose the ability to speak or sing. It is well known that vocal fold dysfunction can range from insufficient movement of the vocal folds to complete vocal fold paralysis. In one vocal fold dysfunction, spasmotic dysphonia, the vocal cords undergo sudden involuntary muscle movements forcing them open or closed and thereby inhibiting the ability to properly phonate. Other factors can affect phonation ability including tumors, muscle tension, or the distance between the vocal cords.
Various devices and methods of treating dysfunctional vocal folds have been developed during the mid to late 20th century and continue to be developed today. One known method uses bulking agents (injected directly into the area around the vocal folds) to support paralyzed or dysfunctional vocal folds. These agents may improve and/or restore the ability to speak in patients with vocal fold dysfunction. Bulking agents used in the past include autologous fat, artificial materials such as hyaluronic acid (HA), radiesse gel, calcium hydroxylapatite, biodegradable microspheres, etc. The challenge with traditional bulking agent injection is that injecting the exact amount of required material is a difficult task. It is possible for too little or too much material to be injected as well for the material to end up in a non-ideal location. Injection of bulking agents in an incorrect amount or location for the application of supporting the vocal folds can result in incomplete correction of phonation problems. The outcome of the procedure is highly dependent upon the skill set of the surgeon performing the procedure and the likelihood of a non-ideal dose of bulking material being administered is high.
In-office bulking agent injection is a procedure which is typically performed under local anesthesia and can provide some level of real-time feedback of how well phonation is improved using an endoscope for visualization. Normally, bulking agents have a limited useful lifespan for the patient, which can range anywhere from about six months to about two years, so this treatment has to be repeated periodically. This method does not offer any post-procedure customization opportunity to further improve phonation.
Another known device and method utilize solid shim-like devices fitted proximal to the vocal folds and adapted to provide support to the folds. One commercial example is the VoCom thyroplasty system, manufactured by Olympus. These shims (also known as hydroxylapatite implants) can vary in size and offer medialization for unilateral vocal fold paralysis. Typically vocal fold displacement can range from about 3-8 mm with the implants and about 0-3 mm with the shims. This system and other comparable devices offer a more permanent solution than bulking agents, and can have an indefinite useful lifespan. Implantations of these solid shim-like devices typically take place local anesthesia and do offer some level of real-time feed-back in regards to phonation. One advantage of this implant treatment may be that placement can generally be better controlled compared to bulking injections. This method does not offer any post-procedure customization opportunity to further improve phonation.
The present invention may be generally described as a device and method that may be precisely placed in proximity to the vocal folds (with a patient under local or general anesthesia). It also can provide improved real-time phonation feedback during the procedure as well as the opportunity for post-procedure adjustments.